Receiver/transmitter having common elements

Abstract

A transceiver including a receiver having a sequential amplifier that includes at least first and second RF amplifier stages coupled together by a delay line. A transmitter in the transceiver includes an oscillator for generating an RF carrier and the oscillator includes the delay line as a phase shifting element. A modulator is coupled to the oscillator for modulating the RF carrier either AM, OOK modulated, FM, FSK modulated, PM, and PSK modulated.

I claim: 
     
       1. A transceiver comprising: a receiver circuit and a transmitting circuit, both of which are coupled to an antenna;   said receiver circuit comprising: first and second series coupled RF amplifiers;   a delay line coupling said first and second series coupled RF amplifiers to form a sequential amplifier;   said first RF amplifier being coupled to said antenna for receiving a first modulated RF carrier signal;   a receiver control circuit coupled to said first and second RF amplifiers for turning OFF both said first and second RF amplifiers simultaneously during transmission and for sequentially turning ON and OFF said first and second RF amplifiers when receiving said first modulated RF carrier signal, said delay line preventing said first and second RF amplifiers from oscillating; and   a demodulator coupled to said second RF amplifier for receiving said first RF carrier signal therefrom and demodulating said first RF carrier signal to generate output data; and     said transmitting circuit comprising: third and fourth series coupled RF amplifiers having sufficiently low gain so as to prevent oscillation between them;   said delay line being coupled across said third RF amplifier to form a delay line oscillator for generating a second RF carrier signal for transmission;   said fourth RF amplifier having an input for receiving said second RF carrier signal and an output for coupling said second RF carrier signal to said antenna; and   a transmit control circuit coupled to said third and fourth RF amplifiers to enable said second RF carrier signal to be modulated with transmission data; and     a transmit/receive switch coupled to said receiver control circuit and to said transmit control circuit for selectively enabling either said reception or said transmission of said first and second modulated RF carrier signals, respectively.   
     
     
       2. A transceiver as in claim 1 further including: said transmit control circuit receiving data; and   said transmit control circuit amplitude modulating said second RF carrier signal that is being transmitted.   
     
     
       3. A transceiver as in claim 2 further including said transmit control circuit turning ON and OFF said third and fourth RF amplifiers to provide on-and-off key (OOK) amplitude modulation. 
     
     
       4. A transceiver as in claim 1 further including: a frequency modulation (FM) circuit coupled between said delay line and said third RF amplifier;   an input terminal for supplying said transmission data to said frequency modulation circuit for frequency modulating said second RF carrier signal; and   said transmit control circuit turning ON said third and fourth RF amplifiers to generate and couple said frequency modulated second RF carrier signal to said antenna.   
     
     
       5. A transceiver as in claim 4 wherein said FM circuit frequency shift key (FSK) modulates said second RF carrier signal with said transmission. 
     
     
       6. A transceiver as in claim 1 further including: a phase modulation (PM) circuit coupled between said fourth RF amplifier and said antenna;   said transmit control circuit turning ON said third and fourth RF amplifiers to generate and couple said second RF carrier signal to said phase modulation circuit; and   an input terminal for supplying transmission data to said phase modulation circuit for phase modulating said second RF carrier signal coupled to said antenna.   
     
     
       7. A transceiver as in claim 6 wherein said phase modulation circuit phase shift key (PSK) modulates said second RF carrier signal with said data. 
     
     
       8. A transceiver as in claim 1 further including a band-pass filter coupled between said antenna and said first and fourth RF amplifiers to filter said first and second modulated RF carrier signals being both transmitted and received. 
     
     
       9. A transceiver as in claim 1 further including: a single integrated circuit including both said receiver and said transmitter; and   said SAW delay line being attached to said integrated circuit to form said transceiver.   
     
     
       10. A transceiver including: an antenna;   an RF receiver including a sequential amplifier coupled to said antenna for amplifying a received modulated first RF carrier signal;   said sequential amplifier including at least first and second RF amplifiers;   a demodulator coupled to said sequential amplifier for detecting data in said received modulated first RF carrier signal;   a transmitter including an oscillator for generating a second RF carrier signal, said oscillator including a phase shifting element;   a modulator coupled to said oscillator for modulating said second RF carrier signal for transmission by said antenna;   switching means coupled to said RF receiver and said transmitter for selectively activating either one of said RF receiver and said transmitter; and   a delay line responsive to said switching means and commonly used in said RF receiver to couple said first and second RF amplifier together only when said RF receiver is activated and in said transmitter oscillator as said phase shifting element only when said transmitter is activated.   
     
     
       11. A transceiver as in claim 10 further including a single integrated circuit including both said receiver and said transmitter, said delay line being attached to said single integrated circuit to form said transceiver. 
     
     
       12. A transceiver as in claim 10 wherein said first and second RF carriers are amplitude modulated (AM). 
     
     
       13. A transceiver as in claim 12 wherein said first and second RF carriers are on-off key (OOK) amplitude modulated. 
     
     
       14. A transceiver as in claim 10 wherein said first and second RF carriers are frequency modulated (FM). 
     
     
       15. A transceiver as in claim 14 wherein said first and second RF carriers are frequency shift key (FSK) modulated. 
     
     
       16. A transceiver as in claim 10 wherein said first and second RF carriers are phase modulated (PM). 
     
     
       17. A transceiver as in claim 16 wherein said first and second RF carriers are phase shift key (PSK) modulated.